A machine is known from German patent document 2,509,506 that conveys a textile web workpiece longitudinally, that is parallel to its warp, along a stretch or path between a pair of longitudinally spaced and transversely throughgoing main rolls rotatable about respective parallel axes. A guide and drive system moves the web longitudinally from one of the main rolls to the other in a travel direction perpendicular to the roll axes and with the web spanned tightly longitudinally between the main rolls and lying generally in a plane. The edges of the web are folded over by respective devices between the stretchers and the downstream main roll and then the folded-over edges are stitched longitudinally to stabilize them.
The web must be relatively tight so it can be accurately selvedged in such a machine. It is therefore standard practice to rotate the downstream main roller, and any other drive means downstream therefrom, at a peripheral speed greater than that of the upstream main roller and any other drive means upstream therefrom. This action tensions the web longitudinally.
Unfortunately with such a system it is frequent that the fabric bellies down where it hangs between the two main drive rollers, which are usually horizontally spaced from each other. This tends to pull in the transverse edges, making accurate selvedging difficult. In addition it leaves the edges shorter than the middle of the goods, measured parallel to the warp, when the goods are released. The resultant workpiece therefore curls up at the ends.
When this problem appears in the production, for example, of towels of terrycloth from goods which have loopfree transverse stripes that are to be positioned adjacent the short ends of the towels when they are cut from the selvedged web, it becomes particularly difficult to make an attractive product. When the tension is wrong the loopfree stripes do no extend parallel to the ends, making the towels into seconds.